ABSTRACT The goal of this project is to conduct a pilot study to test the utility of a Natural Language Processing (NLP) clinical messaging tool to improve the reach and the quality (fidelity and competency) of coaches providing behavioral activation (BA) strategies through a mobile mental health app called Personalized Real-time Intervention for Motivational Enhancement (PRIME). Despite decades of research and development for the treatment of mood disorders, depression has risen from the 5th leading cause of disability to the leading cause in the US. Critical barriers for progress in the field are 1) Poor access to high quality care for consumers; 2) Limited mental health workforce; and 3) Few providers are trained in the delivery of evidence-based treatments. In response to this public health problem, our team is proposing to use a mobile platform to improve access to an evidence based treatment; increase the reach of mental health coaches while supporting the delivery of higher quality of care. We will improve the reach of clinicians by using a NLP-powered messaging tool, which will ensure fidelity to the BA model and clinicians will have access to real-time clinical information about their patients to guide more targeted treatment (competence). By improving the efficiency and competence of mental health coaches in the context of mobile mental health services, we expect patients to make greater gains in depression, mood-related disability, and in achieving personal goals. In order to evaluate the feasibility, tolerability, and overall impact of the enhancements to PRIME, we will spend Year 1 engaging stakeholders in a human centered iterative design process and spend Years 2-3 conducting a pilot randomized controlled trial in which we will randomize 120 individuals with depression to either receive 8- weeks of 1) PRIME 1.0 (current version) OR 2) PRIME 2.0 (version with the NLP-powered clinician dashboard). Using BRIGHTEN, our mobile clinical trial platform, we will recruit participants, consent, screen, evaluate and deliver the intervention entirely remotely. The pilot data from this study will be used to prepare for a R01 study to definitively determine whether PRIME may be used to efficiently and effectively improve outcomes for a significantly larger number of individuals with depression.